This application claims the priority of German application 198 55 562.8, filed Dec. 2, 1998 in Germany, the disclosure of which is expressly incorporated by reference herein.
The invention relates to a crankcase for an internal-combustion engine in a V-arrangement.
A crankcase of this type is known from the publication "MTU Friedrichshafen, Products and Services, Series 880, Edition January 1998". The cross-section of this crankcase has a y-shaped structure. In the area of the crankshaft space, the auxiliary assemblies heat exchanger, filter and oil supply spaces as well as their connection lines are arranged on the outside of the crankcase.
Based on the above-described state of the art, it is an object of the invention to further develop this state of the art.
According to the invention, this object is achieved in that the crankcase is constructed in a parallelepiped shape with a rectangular cross-section. In this case, the base side of the parallelepiped corresponds approximately to the lateral projection in the area of the cylinder heads. In addition, the crankcase has at least one chamber which extends from the longitudinal side of the crankcase into the interior. This chamber is formed of the two crankcase end walls, a portion of the base area and a wall bounding the crankshaft space. According to certain preferred embodiments of the invention, a chamber is preferably arranged on each longitudinal side of the crankcase.
According to certain preferred embodiments of the invention, it is suggested that several chambers be arranged on a longitudinal side, in which case the chambers are separated from one another by one transverse wall respectively, and this transverse wall is constructed in one piece with the crankcase.
According to the invention, the crankcase is constructed as a simple box structure. As it is known, such a box structure has a high rigidity with respect to torsion and bending. The forces resulting from the combustion can therefore be diverted in a targeted manner. It is an important advantage in comparison to the internal-combustion engine known from the state of the art that an internal-combustion engine having the crankcase according to the invention, despite supplying the same power, has a significantly smaller overall size. In other words, an internal-combustion engine having the crankcase according to the invention, has, relative to the same output, cross-sectional dimensions which are so small that a crankcase according to the state of the art with a comparable cross-sectional dimension would have a very poor resistance to bending and torsion. As it is known, the section modulus increases with the 4th power of the height or width of the box dimensions.
As a further development of preferred embodiments of the invention, it is suggested that the auxiliary assemblies heat exchanger, filter spaces and oil supply spaces be arranged in the chambers. As a further development, it is suggested that the auxiliary assemblies, particularly the oil pumps and the oil supply spaces, be arranged in the chambers on one side of the crankcase. In contrast, the heat exchangers and filters are arranged on the other side. This results in the advantage of a clear structuring and therefore in a reduction of the connection lines.
As a further development of preferred embodiments of the invention, it is suggested that one chamber in itself represents a closed oil supply space. As an alternative, several chambers of one side may be connected with one another so that they form a common oil supply space. As a further development, it is suggested that the chambers be closed off with respect to the atmosphere by means of a covering. Thus, the whole oil guiding system is fully integrated in the crankcase--without any separate housing or container. The transition of the chamber used as the oil supply space to the crankshaft space is constructed as a single wall. In contrast, the crankcase from the state of the art and, for example, an oil supply reservoir, represent two separate components. The crankcase/oil supply reservoir connection is therefore constructed as a double wall, in which case the line leadthroughs must be machined and sealed off correspondingly.
As additional constructive measures for increasing the rigidity of the crankcase, it is provided according to certain preferred embodiments of the invention that, in the area of the crankshaft space, the crankcase is closed off by means of a jointly carrying bottom cover. In addition, a crossbar is provided according to certain preferred embodiments of the invention in the area of the base surface in the case of each front or end wall.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.